Lubricating apparatus



Feb. 3, 1959 c. H. MUELLER 2,872,085

LUBRICATING APPARATUS Filed Dec. 21, 1956 isgiiigxunmuuk United StatesLUBRICATING APPARATUS Carl H. Mueller, Pasadena Hills,

McNeil Machine & Engineering Company, Akron, Ohio, a corporation of OhioApplication December 21, 1956, Serial No. 629,928 3 Claims. (Cl.222-376) Mo., assignor Vto The atent gce biased toward this seat by aspring 39 reacting om the stroke operation, and the provision of such agrease gun which is economical to manufacture and reliable in operationfor various grades of grease. Other objects and features will be n partapparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims.

In the accompanying drawings, in which one of various possibleembodiments of the invention is illustrated,

Fig. l is a view partly in side elevation and partly in longitudinalcross section of a grease gun of this invention;

Fig. 2 is an enlarged section taken on line 2 2 of Fig. l; and,

Fig. 3 is an enlarged fragment of Fig. l illustrating a moved positionof parts.

Corresponding reference characters indicate corresponding partsthroughout the several views of the Idrawings.

Referring to the drawings, a grease gun of this invention is Ishown tocomprise a container or barrel 1 for containing a supply of grease. Atone end of the barrel 1 is a pump generally designated P. This pumpcomprises a head 3 screwed on the end of the barrel and having a bore 5extending transversely with respect to the barrel. This bore constitutesthe pump cylinder. A pump plunger 7 reciprocates in the bore or cylinder5. The plunger extends out of one end of the cylinder 5 (the rearwardend `of the cylinder). A hand lever 9 is pin-connected at 11 adjacentone end to the end of the plunger which extends out of the cylinder. Alink 13 is pin-connected at 15 to this end of the lever and pinconnectedat 17 to the head 3. The arrangement is such that by swinging the leveraway from the barrel 1, the plunger 7 is pulled out through ia 'primingor return stroke, and by swinging the lever toward the barrel, theplunger is pushed in through a pressure stroke.

The head 3 is formed with a main lateral inlet port 19 for the cylinder5 through which grease may ow from the barrel 1 into the cylinder 5 whenthe plunger 7 is fully retracted through a full return stroke. In the'barrel is a follower 2l biased toward the head 3 by a spring 23 forforcing grease from the barrel into the cylinder. The forward end of thecylinder 5 is closed by a plug 25. The head is formed with a lateraloutlet port 27 adjacent the forward end of the cylinder. Screwed in theoutlet port 27 is an outlet pipe 29. On the outer end of the pipe is aconventional hydraulic coupler 31.

The forward end portion of the cylinder 5 is enlarged as indicated at 33to provide a forwardly facing valve seat 35 inward of the outlet port27. A valve ball 37 is plug 25. The head P is formed with ,an yauxiliarylateral inlet port 41 for the cylinder 5 inward of and closely adjacentthe valve seat 35 through which grease may iiow'` from the barrel 1 intothe cylinder 5 when the plunger 7 is retracted through a short stroke.yThe auxiliary port 41, as shown best in Fig. 2, is drilled .at an angleintersecting the cylinder 5 at one side. The port 41 is counterbored toform an outwardly' facing valve seat 43 located between the barrel endof the port and the cylinder 5. A valve ball 45 is inserted in the port4l from its outer end for engagement with the seat 43 under pressurefrom the cylinder 5 to block olf flow of grease from the cylinder backinto the barrel through port 41. A conventional iller nipple 47 isthreaded in the outer end of port 4l and closes it. A spring 49 isinterposed between the inner end of the nipple 47 yand a shoulder 51formed in the port 41.

Operation is as follows:

0n a full return stroke of the'plunger 7, the plunger is withdrawn tothe left as viewed in Figs.A 1 and 3 beyond the main inlet port 19v forpriming of the cylinder 5 with grease from the barrel l.. Some greasemay enter the cylinder via the ball-checked :auxiliary inlet port 41,but priming occurs mainly via the wide-open main inlet port 19 to insurefull and rapid priming, even in the case of heavy grease. Then, on apressure stroke of the plunger, the inlet port 41 is closed by the valveball 45 to prevent return of grease to the barrel via port 41, valveball 37 opens, and the charge of grease in the cylinder is deliveredthrough the outlet port 27.

In the case the gun need-s to be used in confined quarters where it isnot possible to take a full stroke of the lever 9 and the plunger 7,-ashort return stroke of the plunger to the point where port 41 is open tothe cylinder 5 (see Fig. 3) will prime the cylinder via port 41. Then,on a pressure stroke of the plunger, the ball 45 closes and the chargeof grease (in this case asmall charge) is delivered through the outletport 27.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained. a

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanying.drawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

' l. Lubricating apparatus comprising a lubricant container and a pump,the pump comprising a body having a bore therein constituting `a pumpcylinder and a plunger slidable in the bore, said 'body having a maininlet intersecting the bore ladjacent one end of the bore whichconstitutes the rearward end of the bore and an auxiliary inletintersecting the bore between the main inlet and the other and forwardend of the bore for ow of lubricant from the container to the bore, saidplunger being slidable in the bore between a fully retracted positionwherein the forward end of the plunger is rearward of at least part ofthe main inlet and a forward position wherein its forward end is forwardof the auxiliary inlet, said body having an outlet in communication withthe forward end of the bore, a check valve in the outlet adapted to openin response to lubricant pressure developedon a forward stroke of theplunger and to close on a return stroke of the plunger, a valve seat inthe auxiliary inlet facing in'the direction of flow toward the bore, andan auxiliary check Valve in the auxiliary inlet engageable with saidvalve seat, said auxiliary check valve being constantly free to moveaway from said valve seat to open on a return stroke of the plunger andadaptedin response to lubricant pressure developed in the bore on aPatented Feb. a,` A1959V forward stroke of the plunger to seal againstsaid valve seat and block off ow from the bore back to the contain erthrough'the auxiliary inlet, whereby the plunger'is adapted either forfull-stroke operation or for short-stroke operation involving retractionthereof from its forward positionI to an intermediate position whereinits forward end is rearward of at least part of the auxiliary inlet andyforward of the main inlet.

2. A grease gun comprising a barrel for containing grease, a head at oneend of the barrel having a bore therein constituting a pump cylinder, laplunger slidable in the bore, a lever carried by the head for moving theplunger, the head having a main inlet intersecting the bore adjacent oneend of the bore which constitutes the rearward end of the bore ,and anauxiliary inlet intersecting the bore between the vmain inlet and theother and forward end of the bore for ow of grease from the barrel tothe bore, said plunger being slidable inthe bore between a fullyretracted position wherein the forward end of the plunger is rearward ofat least part of the main inlet and a forward position wherein itsforward end is forward of the auxiliary inlet, said `head having anoutlet at the forward end of the bore including a portion of largercross section than the bore and being formed so that there is aforwardly facing annular valve seat lsurrounding the forward end of thebore, a spring-biased outlet check valve engageable with said forwardlyfacing valve seat adapted to open in response to grease pressuredeveloped 4 in the bore on la forward stroke of the plunger, a valveseat in the .auxiliary inlet facing in the direction of ow toward thebore, and a check valve 'in the auxiliary inlet engageable with saidvalve seat in the auxiliary inlet, said check valve for the auxiliaryinlet being constantly free to move away from the valve seat in theauxiliary inlet to open on a return stroke of the plunger and adapted inresponse to grease pressure developed in the bore on a `forward strokeof the plunger to seal against said auxiliary inlet vaive seat and blockoff flow from the bore 'back to the barrel through the auxiliary inlet,whereby the plunger is adapted either for full-stroke operation or forshortstroke operation involving retraction thereof from its forwardposition to an intermediate position wherein its forward end is rearwardof at least part of the auxiliary inlet and forward of the main inlet.

3. A grease gun as set forth in claim 2 wherein the auxiliary inlet isconstituted by a passage extending completely through the head andintersecting the bore, said 'passage being formed adjacent its endtoward the barrel with said auxiliary inlet valve seat, the outer end ofthe passage being closed by a filler nipple.

l2,012,923 Bystricky Aug. 27, 1935

